The long-range objective of this research is to determine the etiology and pathophysiology of hermorrhagic disciform macular disease associated with ocular histoplasmosis. Since the pathogenesis cannot be determined in man (because of the lack of histopathologic correlation), an experimental model is required. A successful model of the Histoplasmic choroiditis has been produced in rabbits. The most important experiment, however, is production of the macular lesion. Since monkeys are the only animals whose macular anatomy, structure and function are comparable to those of man, the experimental model must be established, by definition, in primates. Viable yeast phase Histoplasma capsulatum will be injected in one carotid artery of each animal. The course of systemic and ocular disease will be monitored and studied with serial fundus photography, fluorescein angiography, fungal cultures, histopathology, electroretinography, serology, and skin testing. After a reproducible model of disease is developed, long-term studies are proposed to specifically study the late development of macular disciform disease in these animals. The role of inflammation and/or subretinal neovascularization in the development of the macular disease will be elucidated.